Killing in war associated with PTSD and behavioral and adjustment problems

In a study of 1,200 veterans of the Vietnam war, those who reported taking a life in combat had a higher incidence of post-traumatic stress disorder, violent behaviors, trouble with daily functioning, and other psychological problems than those who did not, even decades after their war experience.

The results of the study, which was led by researchers at the San Francisco VA Medical Center
and the University of California, San Francisco, indicated that the negative psychological effects of killing strongly outweighed those of simply being in combat, according to lead author Shira Maguen, PhD, a staff psychologist at SFVAMC.

“Killing, in a variety of ways, turns out to have a wide range of mental health and functioning impacts,” says Maguen, who is also an assistant clinical professor of psychiatry at UCSF. “We knew it would be important, but we were surprised at the extent to which the effects of being in combat faded in comparison.”

The study appears in the October 2009 issue of the Journal of Traumatic Stress.

The authors used data collected during the mid to late nineteen eighties for the National Vietnam Veterans Readjustment Study (1990), a comprehensive U.S. government study of psychological problems among Vietnam veterans who served between August 1964 and May 1975.

They classified respondents into two groups – those who reported killing, or believing that they killed, another person during combat, and those who did not. They then compared the two groups according to various psychological and behavioral measures: PTSD; violent behaviors; functional difficulties in areas such as employment, relationships, legal problems, and substance abuse; and dissociation, a mental state in which a person experiences a sense of separation from his or her own thoughts or feelings. The 47 percent of veterans who reported killing scored significantly higher in all those categories than those who did not.

Maguen stresses that the study was not designed to investigate why veterans who killed had more psychological difficulties than those who did not, and that the results need to be replicated in future studies. However, she says that in her own clinical practice, she has observed that the act of taking a life can have a profound effect on a veteran of war: “In the military, you’re trained to shoot at a target, but sometimes the humanity of that target intrudes, and people come to question what they’ve done.”

The study authors emphasize the relevance of their results for the current generation of troops serving in Iraq and Afghanistan, citing previous research indicating that up to 65 percent of service members returning from the war in Iraq report killing an enemy combatant, and up to 28 percent report being responsible for the death of a noncombatant.

“It’s very important to systematically assess and address the impact of killing,” says Maguen, “and to evaluate it in the most sensitive and supportive way we can.”

Co-authors of the study are Thomas J. Metzler, MA, of SFVAMC; Brett J. Litz, PhD, of the Department of Veterans Affairs Boston Healthcare System and Boston University School of Medicine; and Karen H. Seal, MD, MPH, Sara Knight, PhD, and senior author Charles Marmar, MD, of SFVAMC and UCSF.

The study was supported by funds from the Department of Veterans Affairs.

SFVAMC has the largest medical research program in the national VA system, with more than 200 research scientists, all of whom are faculty members at UCSF.

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